Controller for electric motors.



G. H. WHITTINGHANL,

CONTROLLER FOR ELECTRIC MOTORS.

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Patented Jul; "26; 1910. L

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MANUFACTURING COMPANY OF BALTIMORE CITY, A CORPORATION OF MARYLAND.

CONTROLLER FOR ELECTRIC MOTORS.

-, Specification of Iietters Patent. Patented July 26, 1910. I

Application filed June 21, 1909. Serial No. 503,435. v

To all whom it may concern:

Be it known that I, GEORGE. H. Wmrrinc- HAM, a citizen of the UnitedStates, residing at Baltimore, in the State of Maryland, have inventedcertain new and useful Improvements in Controllers for Electric Motors,of which the following is a specification.

This invention relates to improvements in motor controlling devices, itspurpose being tolprovid'; means for adapting the ordinary timecontrolled .starter 'to conditions for,

which said starters have not heretofore been entirely satisfactory.

In the operation of some kinds of machines, such as printing presses,with individual motors, it is necessary to provide means for operatingthe motor at difierent speeds for difl'erent classes of work, and it isalsonecessary, under some circumstances, as when threading a web ofpaper into a large printing press, to start and stop at short in:tervals, with the regulator set for a low speed. Under such conditionsthe ordinary time controlled starter has not heretofore beensatisfactorily used for several reasons, but principally because of thetime consumed in cutting out the starting resistance at each startingoperation and because of the necessity for retaining a sufficient amountof regulating resistance in. circuit for operation at low speeds forlonger or shorter periods of time.

a In carrying out my invention Iprovide an automatic time controlleddevice for bridging the successive contacts of the starting resistanceand a manually controlled de vice for connecting the contacts of thestarting resistance with the contacts of the regulating resistance,these resistances and contacts being so arranged that the manuallycontrolleddevice in one of its extremepositions will cutout the startingresistance and include the regulating resistance in' the armaturecircuit and in its other extreme position will include the startingresistance and cut out the regulating resistance, and in intermediatepositions portions of the starting and regulating resistances will becut out and the remaining portions will be 1 included in series with oneanother and with the'armature. By these means, as will be I made clearin the following description, in

operating at any speed below the normal,

the proper amount of current will be admitted to the armature before thetime controlled element has completed its movement, and during thelatter part of its movement said element will not operate to eliminateresistance from the armature'circuit. For operating at speeds above thenormal an auxiliary device may be used for inserting resistance in thefield circuit automatically after the time controlled device hasoperated, but this field resistance can only be inserted when themanually controlled switch is set in position to permit all of theresistance to be cut out of the armature circuit. i

In the accompanying drawing which illustrates my invention, Flgure l'isa front view of a controlling mechanism in which the circuitingbar-which makes butt contacts, in

tact members connected to the successive sections of the startingres1stance,'thec1r- Fig. 2 is a diagrammatic view of a controllingmechanism in which the short circuiting bar of the time controlleddevice is arrangedto move in sliding engagement with a series ofcontacts connected to the starting resistance erating devicesaremounted, B indicates a time controlled-starter and C indicates a mapually controlled switch-arm. The starter B comprises a solenoid 1 ,a dashpot or other suitable retarder 2, connected to thecore 1 of thesolenoid, a short circuiting bar 3, suitably supported upon the upperend of the solenoid core and provided with contact pieces i"1 adapted toengage cotiperating contacts 8l1 respectively. The contacts 8-41 aresecured to the lower ends of rods 12 adapted to slide vertically insuitable brackets 13 and these rods are connected by flexible loads14.17 to the ends of successive sections 7", r, rtand 1' of a startingresistance R. The ends of the starting resistance sections are connectedto a series of segn'lental vcontact pieces 18 22 arranged concentricwith the pivot '23 of the switchnrm C, which is adapted to engage saidconvtact pieces. Conductors 24 and 25 connect the first contact piece 18in the series with one terminal 26 of the supply circuit switch S, andthe short circuiting bar 8 isconnected t0 1 the same terminal of saidswitch by conductime-controlled starter comprises a shortsuccession,with a series of cooperating concuits being shown diagrammatically; and,

Referring to F ig. l of the drawing A indicates a suit-able panel, uponwhich the optors 24 and 27 The contact members 8, 9,

- and 11 are arranged at successively greater distances from thecontacts 4, 5, 6 and 7 so forms a low resistance circuit not only aroundthe entire starting resistance but between the contacts of successivesections. A regulating resistance T is provided with a series ofcontacts pieces to t, inclusive, arranged concentrically with respect tothe pivot 23 and the lever O is adapted to engage any one of thesecontact pieces 'and connect.

it with one of the segmental contact'pieces 18-22 of the startingresistance. One endof the regulating resistance is connected throughconductor 28 to the armature 29 of a motor M and thence throughconductors 30 and 31 to the terminal 32 of the supply circuit switch S.The shunt field winding 31 of the motor is connected at one end to' theconductor-30 and at the other end to a conductor 33 which is connectedto a switch lever 34L, which is adapted to insert or re- I -move a fieldresistance 35, and this field resistance and'lever are connected by aconductor 36 to the supply switch terminal 26. The solenoid 1 may be"connected in any suitable way so that the current will pass through itswindings when the supply switch S isclosed and the solenoid will bedeenergized when'the supply switch is opened. As shown in the drawing,the solenoid is connected across the line by conductors 37 and 38 whichconnect with the conductors 2,4 and 31 leading to',

the supply switch terminals. As shown in the drawing, the resistancesand their adjacent contacts'are so arranged that if the .manuallycontrolled switch member C is moved on to the contacts 5 and 18 and thesupply switch S is then closed, the current to the armature will flowthrough the regulating resistance, which is then in series with thearmature, but no current can flow through the starting resistance as thelatter is not, in this position of the lever C, in series ,with thearmature. This assumed position'ofthe lever C is the position .for thelowest speed of the motor and the regulating resistance T f aflords fullprotection to the motor armature when the current is admitted so thatthere is no need of having the starting resistance in circuit Therefore,although the solenoid 1 gradually lifts the short circuiting bar 3 intoengagement with the contacts 8-11, after the closure of the'su plyswitch S, no

change in the resistance 0 the armature circuit results by re'asoniofthis automatic operation', andthe motor, at the instant of closing thesupply switch S, receives all of the current that it is desired to admitto the armature for operation at this slow speed,

. usual starting current will flow through the contact 18, switch lever0, contact t, the entire regulating resistance T and conductor 28, andthence by way of conductors 30- and 31 to the opposite side of thesupply switch.-

If it is desired to have the motor operate at normal speed, theswitch-arm C is moved over until it connects the last contact 22 of vthe starting resistance with the contact t at I the end of theregulating resistance. This will connect the starting resistance inseries with the motor. armature and cut out all:of theregulatingresistance; Then, when the supplyswitch is closed, no current will passthrough the regulating resistance, but the startingresistance, and thesolenoid-1 will move the short circuiting bar '3 upward and graduallycut out the starting resistance so that the motor will run at normalspeed. If

it is desired to operate the motor at a speed intermediate its highestand lowest speeds,

the switch lever C is moved to an intermediate point.

'In the drawing the lever O is shown in engagement with the contact t ofthe regulating resistance and the contact 19 of the starting resistance.In this position of the lever it will be seen that the first section 7-of the starting resistance is connected through the switch lever inseries with that I part of the regulating resistance which is betweenthe contacts t? and t", while the sections r, 1 and 1" of the startingresistance and the sections of the regulating resistance between thecontacts 5 and t are out out of the armature circuit. In theposition ofthe lever C shown in Fig. 1 of the drawin when the switch S is closed,current wil flow to the armature, through the section 7 of the startingresistance, and thence through the main part of the regulatinresistance. As the solenoid 1 lifts the s ort circuiting bar, thecont-acts 4 and 8 will engage, thus cutting out the section 7* of thestarting resistance, and leaving only the main part of the regulatingreslst'ance in se- The shortrice with the motor armature. circuiting barthen en ages thecontacts 9,-

,10 and 11, successive y, but performs no function in so doing. If theswitch-arm C is set so'as to engage the contacts 20 and t or t"', thesections 1" and r of the starting resistance will be included in serieswith that portion of the regulating resistance between the contacts 6''or t, and the contact t. Upon the closure of the line switch thesections r, r of the starting resistance will be automatically cut out,in succession, leaving about one-half of the regulating resistance inseries with the armature for controlling the speed, while the engagementof the short-circuiting bar 3 with the contacts 10 and 11 will not varythe resistance in the movement.

the motor at normal speed, of course the annaturevcircuit. Similarly ifthe arm C is in the resistance of the armature circuit.

By the means above described, it will be seen that when the arm C is setto operate the motor at the lowest speed, the automatic starter performsno function and no time is lost in waiting for the starter to operate,while when the arm is set to operate at intermediate speeds, the motorisprotected at first by parts of the starting and regulatingresistances,and all of the starting resistance in circuit with the armature is cutout before the starter ceases its Vhen it is desired to operate fullstarting resistance'is required to be in circuit and this is not cutoutuntil the starter has engaged all of its contact points.

If it is desired to operate the motorabove normal speed, auxiliarydevices may be provided for inserting resistance in the shunt fieldcircuit of the motor after the last section of starting resistance hasbeen cut out; This may be done by arranging a pivoted switch arm 3.4above the rod 12* so that when the short circuiting bar 3 moves the rod12 upward, the latter will move the switch arm 34 to include more orless of theresistance in the shunt field circuit.

Normally this switch lever 34 is locked against upward movement by a rod40 arranged on the back of the panel A and having over-turned ends 41one of which is adapted to bear against a shoulder 42 on the lever 34while the other bears against a cam43, rotatable about the pivot pin 23with the switch arm C. This cam is concentric with the pivot 23exceptifor the de- '-pression 43 which comes opposite theuppcr end ofthe rod 40 when the arm C is moved into engagement with the contactstuds or buttons 29 or t. When the arm Chengages these buttons theregulating resistance T is cutout of the armature circuit and thestarting resistance is entirely included in the armature circuit and therod 40 is 'free to move upward into the depression in the cam andtherebyallow the switch-arm 34 to be moved upward by the rod 12* whenthe latter is movedby the short circuiting bar 3. -Therefore,,in thisassumed position of. the switch arm C, after the last section of thestarting resistance is cut out by the engagement of the contact 7 withthe contact 11, the rod 12 is moved upward and' lifts the arm 34 toinsert more or less of the field resistance 35 according to thedistancewhich the cam surface 43 permits the rod The field resistanceisthus'cut out when the motor is stopped, and inserted at the completionof the starting operation provided the switcharm C is in'its right handposition and engaging the contacts or If the switch arm is out ofengagement with these contacts then the cam 43 holds the 'rod 40 againstthe shoulder on the lever 34, so that the latter can notbe moved upwardwhenthe rod 12 is engaged by, the Y short circuiting bar 3. v

In order to insure a good electrical connection between the shortcircuiting bar and the stationary contacts of the regulating resistancea yielding brush 45 may be arranged above a central contactpoint' 46 onthe short circuiting bar and this yielding brush contact may beconnected by a con ductor 47 to the lever at its pivotal point.

In Fig. '2 of the drawing is shown amodification-of the above describedarrangement, omitting the field regulating resistance. In this latterfigure, a lever 50, mounted upon a pivot 51, is provided with an arcuateshort circuiting bar or arm 52 adapted to slide upon and electricallyconnect a series of contact pieces 5359 inclusive, whioh are ar rangedconcentrically with respect to the pivot 51 and connected to successivepoints in a starting resistance R. This arm is movable, when the supplyswitch Sis closed, by a solenoid 60 and the upward movement oi the armisretarded by a dash pot 61. The con-l tacts 53-59 are connected by leads62v to a corresponding number of contacts, 63-69, which arearrangedconcentricall with respect to the pivot point of a switch lever 71.Another series of contacts 727 8 connected with a regulating resistanceT, are arranged parallel with the contacts 63-69 so that the lever 71,in any of its positions, willengage one contact of each series and thusconnect the start ng resistance with the regulatmg resistancef The arm71, inFig. "2, performs the same function as the arm C in Fig. 1. In itslowest position, shown 1n the draw-;

'ing, the arm 71 cuts out-the starting resistance and includes'theregulating resistance in series with the armature of the motor M and inits uppermost position the arm 7licuts out the regulating resistance andincludes the of the motor. In the normal position of the lever 50 thearmature circuit extends from,

' the terminal 32 of the supply switch, through conductor 79 to thearmature '80 of the mo-- tor, thence through conductor 81, to the last.contact 78 of the regulating resistance,

thence through said 'resistanceto the contact 72, thence throughlever'71, contact 63, lead 62 and contact- 5'3- of the. starting resistance,

1 2 0 starting resistance in series with the armature thence throughswitch arm 50 to conductor ply'switch, through the'conc'lucto-r 79, andatits opposite end through conductor 84 to the opposite side of thesupply switch. The windii s of the solenoid 60 are connected by conuctors 85 and 86 to the terminals of the supply switch throughconductors 79 and 82, respectively. 4

In operation, if the motor is to run at its lowest 'speed the manuallycontrolled arm 71 is set in its lowest position, as shown in thedrawing, so as to include all of the regulating resistance andshort-circuit the starting resistance. Upon closing the supply switch S,the solenoid lifts the arm 50 and the short-ci'rcuiting bar or arm, 52moves slowly upwtrd connecting the contacts 53 59, successively, butthis does not either cut out or insert starting resistance as the arm52remains in engagement withthe contact 53 and thus a ath of lowresistance is afforded to the contact 63 and through the lever 7 1' to-.the regulating resistance, which is in series with the armature.Therefore, in the lowermost position of the switch arm 71 the automaticstarter will perform no function. .If the switch arm 71 is moved toengage the contacts 7 8 and 69 the. regulating resistance will beexcluded and the starting" resistance included 1n the armature clrcult.

Then, when the switch S is closed the starter will automatically andslowly cut out the startin resistance, in the usual way, to

. bring t e motor up to full speed. In anintermediate' position of thelever ill, for an intermediate speed, the arm 7 -1 will connect part ofthe regulating reslstance in series with part of the startingresistance. Thus,.

for instance, if the lever 7 1 is moved toengage the-contacts 75 and 66,the upper half of the regulating resistanceand the lower half of thestarting resistance will be in ser1es.- Then, when the supply switch Sis closedi the upward movement of the arm 50 an bar 52 will cause thegradual elimination of the lower half of thestarting resistance, andduring the remainder of the movement of the arm 52 no resistance will becut-out.

Since the-bar 52 will have a direct connection' with the contact 56,even in the uppermost osition of said. bar, the current may .flowirectly from the supply circu'it'switch through the arm 50, bar 52,contact 56, and

lead 62 to the contact 66, thence through the lever 71 and contact? 5 tothe 11 per half of the regulating resistance and t ence to the motorarmature.

eing therebydeenergized, releases its core and the arm 50 drops to itslowermost position.

'In this invention it. will be noted that the It will be understood, "ofcourse, that when the supply switch S is, opened, the solenoid (30,

tamed, so far as bridging the inoperative portion of the startingresistance'iscon-,

cerned by connecting the bridging arm for the starting resistancecontacts to the menu ally controlled switch instead of to t-heaustomatic starter. Thus, for instance,.in

2, the bridging arm 52, instead of being con nected to the lower side ofthe arm 50 might be connected'to the upper side of the arm 71 I so as toengage the contacts 63-69, with the same result, as will'be obvious.

' I What I claim is: I

1., A motor controlling mechanism comprising a switch member, adjustableat will, a regulating resistance governed thereby, an automaticallymovable member, a starting resistance governed jointly by said twoadaptmembers, one of saidmembers being e started to bridge successiveportions of t mg resistance.

2. A motor controlling mechanism comprising starting and regulatingresistances for the armathre circuit, a switch member adjustable at willfor varying the relative amounts of said resistances in said circuit, a

second member for cutting out said starting resistance and means formoving said latter member automatically, one of said members beingadapted. to bridgesuccessive. portions 1 of the starting resistance.

3. In a motor controlling mechanism,

starting and regulating resistances for'the armature circuit, a swltchmember connect'- in'g said' resistance, said member being adapted,amount of one resistance in circuit andde crease the amount of the otherresistance in circuit, and means for bridging successive portions of thestarting resistance.

- 4. In a motor-controlling mechanism, starting and regulatingresistances, means for cutting out the starting resistance comprisingmeans for bridging successive-sections thereof, and means connectingsaid re- .siistances and adapted to render more or less (of oneresistance operative and more or less of the other resistancelnoperatlveat will.

5. A controlling mechanism for electric.

motors com rising starting and regulating resistances tor the armaturecircuit, means for-cutting out the starting resistance and independentmeans, adjustable at will, for rendering more or less of the starting resistance inoperative and for rendering more when moved, to increase themotors com rising starting and regulating resistancesor the armaturecircuit, automatic time controlled means for cutting out the startingresistance and means, adjustable at will, for rendering more or less ofthe starting resistance inoperatiye and for rendering more or less ofthe regulating resistance operative and vice versa. 7

8. A controlling mechanism for electric motors comprising starting andregulating resistances for the armature circuit, means for cutting outthe starting resistance and independent means, adjustable at will, forrendering more or less of the starting resistance inoperative and forsimultaneously rendering more or less of the regulating resistanceoperative and vice versa.

9. A controlling *niechanism for electric motors comprising starting andregulating resistance for the armature circuit, autogmatic means forcuttin out the starting re sistance and means, a ustable at willgt'forrendering more or less of the startingresistance inoperative and forsimultaneously 1152111, v U 4 I v i the starting resistance out out bysaid n1emdering more or less of the regulatingresistance operative andvice verse}; I l

10. A controlling mechanismlfor.electric motors comprising starting andregulating resistances for the armature circuit, automatic timecontrolled means for cutting out the starting resistance and means,adjustable at Will,'for rendering more or less of the startingresistance inoperative and for simultaneously rendering more or less ofthe regulating resistance operative and vice versa. a

11. A controlling mechanism for electric motors comprising starting andregulating resistance for theiarmature circuit, a switch. member,adjustable at will, adapted, when moved, to cutout starting resistanceand. in sert regulating resistance, or vice versa, independent means forcutting out that part of the starting resistance which it not cut out bysaid member, and means for bridging or short-circuiting the portions ofthe startingresistance which are cut out by said member.

12. A controlling mechanismfor electric motors compris'ing starting andregulating iyasistances for the armature circuit, a switch member,adjustable at will, adapted, when moved, to cut out starting resistanceand insert regulating resistance, or vice versa, automatic means forcutting out that part of the starting resistance which is not cut outportion of the starting resistance which is cut out becomes bridged orshort-circuited.

13. A controlling mechanism for electric motors comprising a starter, aregulating resistance, a switch member, adjust-able at will, connectingthe regulating resistance with the starting resistance, and adapted,when moved, to cut out starting resistance and insert regulatingresistance, or vice versa, said mechanism comprising-means whereby thestarting resistance cut out by saidimemher is bridged orshort-circuited.

14. A controlling mechanism for electric motors comprising an automatictime con trolled starter, a regulating resistance, a

ing the regulating resistance-with the starting resistance, and adapted,whenmoved, to out out the starting resistance and insert regulatingresistance, or vice versa, said mechanism comprising means whereby thestarting resistance cut out by said member resist-ances in circuitincrease the amount of, the' Totl 'e'r orsa1d resistances 1ncircuitand-me'ans whereby that portion 0t ber may be Tshort-circuitedandthe balance. of the startin resistance may be cut out or shortcircuite 4 16. The combination with an automatic starter comprising astarting resistance, andv means for bridging successive contact sunfaces of said resistance, of a regulatin {,re sistance, a switchmemberconnecting sai 'iesistances, said member being adapted,when moved, toincrease the amount of one resistance in circuit and decrease the amountof the other in circuit.

17. The combination with an automatic starter comprising a startingresistance and means for bridging successive contact Surfaces of saidresistance, of a regulating resistance, a switch member connecting saidresistances, said member being adapted,

include all of the regulating resistance, and when moved to its otherextreme position, to cut out all of the regulating resistance andinclude all of the starting resistance.

18. In a motor controlling mechanism a starter comprising a bar or armadapted to connect the various contact 'points of the startingresistance electrically together, a

switch member, adjustable at will, connectwhen moved to one of itsextreme positions,; to cut'out all of the starting resistance andby saidmember, and means whereby that taneously decrease the amount of one ofsaid iii 0 regulating resistance and a switch member- "conne"cting' saidresistances, adjustable at electric motors comprising an automaticstarter, a regulating I'eSlStilIiCQ for the armafture circuit, amanually controlled switch mein'ber adapted to cut out" said regulatingresistance and insert the starting" resistance,

a field regulating resistance, means movable the starter,'for insertingsaid field regulating resistance when the armature regulat 1n resistanceis cut out and means adjustable by said manually controlled switchmember for preventing the insertionof field resistance except 'Whenthearmature regulazing resistance is cut out.

In testimony whereof I afiix my signature, 20

in presence of two Witnesses.

, {GEOR E H. 'WHITTr-NGHAM Vitnesses:

CLAY JEWELL, WILLIAM C. OBRIEN."

